As new materials, such as composite materials, are used in more applications throughout the aircraft and other industries, the use of nondestructive test equipment, such as ultrasonic test equipment, to inspect fabricated parts prior to use has become widespread. Ultrasonic test equipment allows an operator to nondestructively inspect the interior of parts, such as a wing or control surface panel, for flaws and other areas of discontinuity such as delaminations, foreign objects introduced during fabrication, etc.
Ultrasonic test equipment works by generating a high frequency sound wave at an ultrasonic transducer located near the surface of the part being tested. The ultrasonic transducer is oriented such that the high frequency sound wave travels through the part, usually in the height or thickness direction. When the sound wave contacts a discontinuity, such as a flaw, delamnination, or a change in the stiffness of the material, part of the sound energy is reflected. The reflected sound energy travels back through the part and is received by the same ultrasonic transducer, which acts as both a transmitter and receiver in what is commonly referred to as a "pulse echo" ultrasonic test system. Alternatively, the high frequency sound wave generated by the ultrasonic transmitter passes through the entire thickness of the part and is received on the opposite side of the part by a separate receiver in what is commonly known as "through transmission" ultrasonic testing. Pulse echo ultrasonic testing is the most common technique in use because access to only one side of a part is required. While useful with through transmission ultrasonic testing apparatus, as will be better understood from the following description, the present invention was developed for use with pulse echo ultrasonic testing apparatus.
The waveform of the received RF signal from an ultrasonic test is recorded by the test equipment and/or displayed on a monitor or other display device. The data contained in the RF signal can be displayed in a number of different formats. The most commonly used display format is called a "pulse echo." A pulse echo is basically a top down view of the portion of the part that has been ultrasonically tested. A pulse echo gives the operator a general idea of the size and shape of any discontinuities within the part in the height or thickness direction.
Alternatively, the ultrasonic data may be displayed in the form of an A-Scan, a B-Scan, or a time of flight display. A B-Scan displays the ultrasonic data in a way that graphically portrays the cross section through the thickness of the test part while an A-Scan is simply the RF signal plotted as a graph of time versus amplitude of the signal. A time of flight display is the ultrasonic data displayed in a way that shows a top down view of the area scanned graphically portraying the distance into the part to the point where a discontinuity is located.
Prior art ultrasonic test equipment generally displays a real time continuous A-Scan as the ultrasonic transducer moves along the part and also records the data used to produce a pulse echo. During scanning or after testing, the pulse echo is typically output as a hard copy to be saved for later reference. Generally, the entire RF signal is not recorded by the test equipment, thus once a scan is complete, a test must be reperformed if any additional information is desired. Prior art systems do not allow an operator to simultaneously view the B-Scan, pulse echo, A-Scan or time of flight display to get a better understanding of the ultrasonic data. Nor do prior art ultrasonic test systems allow the operator to view a display of the ultrasonic data, select a portion of the data that is particularly relevant, and create other displays based upon the operator's selections.
Typically, in the past, a user will examine the B-Scan or pulse echo during testing in an attempt to locate flaws. If a flaw is located, the user will reprogram the test equipment to obtain additional test data in the area where a flaw is observed. It is not uncommon for a user to perform and observe a B-Scan display during testing and once a flaw is located, repeat the test while observing a pulse echo display and then repeat the test again observing an A-Scan or time of flight display to obtain a better understanding of the test results. Obviously, this approach is very time consuming and, thus, undesirably expensive.
One goal of the ultrasonic analysis and display system of the present invention is to allow a user to simultaneously view ultrasonic test data in a number of different display formats and to manipulate the displays in order to rapidly and quickly obtain a better understanding of the data while eliminating some of the problems present in the prior art.